Method of making fishtail bits



April 1931- c. w REHBACK 1,799,318

METHOD OF MAKING FISH TAIL BITS Filed Aug. 51, 1927 mvemov; QHeRLEs w. muse m BY \e $47044 W mum QTTOQNEYS Patented Apr. 7, 1931 UNITED STATES CHARLES WALTER REHBACK, F REDONDO BEACH, CALIFOFNIA.

METHOD OF MAKING FISHTAIL BITS Application filed August 31, 1927. Serial No. 216,591.

This invention relates to improvements in rotary fish tail bits and to a means and method of constructing the same. The invention may be considered as an improvement over the invention disclosed in the United States Patent No. 1,547,842 issued July 118, 1925, to Winston F. Stoody, et al.

In rotary fish tail bits it is highly desirable that the bottom cutting edges and the wings 16' of the bit be reenforced, that is, that these bottom edges and side edges of the bit be relatively'thick and formed of a hard tough metal which will withstand abrasion while drilling. In the prior patent above referred to, wings on the bit are formed of such a metal, these wings being provided by depositing a molten metal on the body of the bit as by welding, and thus building up the thick wings of the desired material. However, when the desired material is deposited on the body of the bit by welding, it has been found that it is diflicult to get a thick heavy bottom cutting edge on the bit by this method. The bottom edge of the body of the bit is relatively thin, and when the welder attempts to deposit a large quantity of metal on this edge, it fre uently happens that-instead of depositing t e metal he burns through the edge of the body of the bit. Consequently, it is very diflicult for persons other than expert and experienced welders to properly con-- struct a bit in this manner to have the desired shape and form.

This invention provides an improved means bit such that practically any welder, regardless of his experience or ability, can construct a rotary fish tail bit or reconstruct one with the desired shape and form and have the desired metal forming the cutting edges and wings.

Another object of the invention is to provide a section adapted to be applied to a fish tail bit body such as by Welding or any other securing means which will form the bottom cutting edges and the wings of the bit in the desired manner.

With the foregoing and other objects in.

view which will be made manifest in the foland method of constructing a rotary fish tail pointed out in the appended claim, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a View in front elevation of a rotary fish tail bit constructed in accordance with this invention.

Fig. 2 is a view in side elevation of the same.

Fig. 3 is a sectional View takenupon the line 33 upon Figure 1.

Fig. 4 is a view in 'front elevation of the section adapted to be applied to a fish tail bit body to form the desired construction of the bit.

Fig. 5 is a view in side elevation taken in the direction of the arrow 5 upon Figure l.

Fig. 6 is a View similar to Figure 4, illustrating a slightly modified form of construction.

Fig. 7 is a vertical section illustrating the manner in which an old fish tail bit can be reconstructed in accordance with this inven tion.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, in order to construct the improved bit, a fish tail bit body 10 which may be of any conventional construction having the threaded pin 11 and discharge ports 12, is first provided. Two sections generally indicated at 13 and 14 are then provided, these sections being formed of a relatively hard tough metal which can withstand abrasion. These sections are ap- 35 proximately L-shaped in form, having their outer edges formed so as to correspond to the side and bottom edges of the fish tail bit body 10. As clearly shown upon Figures 3 and 5, the outer edges of these sections are materially thicker than the inner edges,the vertical outer edge being shown thicker at 15 and the bottom outer edge being shown thicker at 16. The bottom edges of the sections 13 and 14 form the bottom cutting edges of the bit and extend toward the cen ter of the bit to a point near the central notch 17. It is not necessary to have the sections provide the edges within the notch 17 for the reason the; the wear on the edges forming the notch is very slight because these edges are near the center of the hole drilled by-the bit. The sections 13 and 14 are positioned upon the opposite faces of the 5 bit body near the lower right hand corners'of these faces. They are rigidly and permanently secured in place in any suitable manner, preferably by welding such as is indicated at 18. In welding the sections to the body of the bit it is desirable to work as much metal between the back of the section and the face of the bit as possible, so that the body of the bit together with the deposited metal from the welding will form a good backing for the sections. The sections are also welded along their outside edges as indicated at 19, and along their bottom edges. In the modifications shown in Figures 1 to 4 inclusive, apertures 20 are formed through the sections and metal may be deposited through these apertures so as to tack the sections 13 and 14 to the body of the bit.

From the above described construction it will be appreciated that the heavy bottom cuttin edges and that the heavy wings are provi ed by a separate section of material which is fastened securely to the body of the bit. The separate sections can be cast from a hard alloy, and in that manner the will be given the proper shape to provide t e desired heavy cutting between edges and wings. No particular skill is required to properly fasten the sections in place against the opposite faces of the body 10, and at the same tlme, the bit will have the proper form such being obtained from the shape of the sections 13 and 14. i

In the modification shown in Figure 6, the section 21 is substantially the same in form as the sections 13 and 14, except the apertures 20 are omitted. These apertures can be employed or omitted as desired, or their number ma be increased over the number shown in Flgures 1 and 4. By means of the sections provided for constructing the bit, an old bit which has beenpractically worn out can be easily and quickly reconstructed and given the proper form. The method of accomplishing this is illustrated in Figure 7, wherein an old body of the bit is shown at 10 hav' its bottom edge indicated at 22, this edge aving been worn ofi by, the previous use of the bit. To reconstruct the bit,

sections 13' and a corresponding Section 'cor a support for the molten metal 23 while being deposited, and assists in moulding it into the proper form.

From the above described construction it will be appreciated that a novel means and method is provided for constructing a rotary fish tail bit which is of improved construction, in that the bottom cutting edges and the wings of the bit will have the desired shape and form, and will be formed of the desired quality of metal which will withstand abrasion.

It will be understood that various changes in the details of construction may be made without departing from the spirit or scope of the invention as defined by the, appended claim.

I claim:

The method of constructing a. rotary fish tail bit comprising providing a fish tail bit body, forming sections of relatively hard material which are adapted to form wings and bottom cutting edges for the bit, positioning said sections against the opposite faces of the bit adjacent a bottom and side edge thereof, and depositing metal as by welding about said sections and upon the back. thereof, thus securing the sections to the body of the bit and forming a strong backing for said sections.

In testimony whereof I have signed my name to this specification.

CHARLES WALTER REHBACK.

responding to the section Mare positioned on opposite faces of the body 10' and welded against the face of the bit. Metal is then deposited on the back of these sections such 60 as by welding, this metal being indicated at 23. The metal 23 serves to build out the bottom of the bod 10 and to rigidly connect the bottom e ge 22 to the back of the section 13. The section 13 after having been secured to the face of the bit, serves as 

